1792 / 2019-08-29 15:39:31

Analysis of water vapor effects on aerosol properties and direct radiative forcing in China

19、气溶胶与大气环境科学 > 专题4：气溶胶物理化学过程、新粒子生成

The effects of column water vapor (CWV) on aerosol optical, radiative properties and classification are studied by using aerosol and CWV data from eight Aerosol Robotic Network (AERONET) sites in China: Beijing, XiangHe, Shouxian, Taihu, Hong_Kong, Zhongshan_Univ, SACOL, and Mt_WLG, which represents 5 distinct aerosol climatologies in China. Contrast in correlations between aerosol optical depth (AOD) and CWV is found. High correlation coefficient (R) ranging from 0.63-0.94 is observed at Beijing and XiangHe (North China Plain), SACOL (Northwest China) and MT_WLG (the Tibetan Plateau). R values at stations in the Middle-Eastern China (Shouxian and Taihu) are within 0.32-0.45. AOD shows poor correlation to CWV in Southeast China (R at Hong_Kong and Zhongshan_Univ of 0.15 and 0.27). At most sites, the asymmetry (ASYM) of fine-mode aerosol increases with CWV with R larger than ~0.4. Aerosol direct radiative forcing efficiency (ADRFE) at the bottom of the atmosphere (BOA) is affected by CWV, with R > ~0.5 over the north and Middle-East China sites. The statistic results show that an increase of CWV by 0.1 cm could result in enhancements of ADREF at the BOA by about 1.1~2.8 W m-2 at all the sites except Mt_WLG. The aerosol classification shows that the high CWV always corresponds to the mix-small particles. The clusters of back-trajectories with relative humidity (RH) from HYSPLIT model indicate that the air mass with high RH is often from south and east regions and high CWV sites are often undergone by high RH air mass flows. The influence of CWV on aerosol properties is mainly shown in the properties of fine mode aerosol and the CWV also need to be considered for air pollution prevention and control especial for the haze.